This invention relates to a ring-like, resilient insert which may be optionally used within a conventional pipe coupling gasket mounted within a conventional pipe coupling for connecting adjacent ends of aligned pipes.
Conventional pipe couplings which are used to connect the ends of water pipes and the like, which pipes are provided with exterior connection grooves, generally are formed of a circular casing or housing made of two semi-circular segments that are connected together to encircle the adjacent pipe ends. The segments are U-shaped in cross-section with a circular base and inwardly extending legs having free ends that engage within the pipe grooves. Thus, the inner edges of the legs form keys or tenons, which extend within the grooves in the exterior surfaces of the pipes for positively holding the pipe ends together.
A conventional rubber-like resilient gasket is arranged around the adjacent pipe ends and within the coupling casing or housing. That is, the two segments that typically form the casing are positioned around the gasket with their legs enclosing the gasket. The gasket typically is formed with lips on the inner ends of the legs for encircling and engaging the adjacent pipe peripheral surfaces.
Examples of such couplings are illustrated in my prior U.S. Pat. No. 4,966,395, issued Oct. 30, 1991 for a "Rigid or Flexible Coupling for Pipes" and in U.S. Pat. No. 4,915,418, issued Apr. 10, 1990 to Josef Palatchy for a "Hinged Pipe Coupling". Other patents illustrate similar types of devices within which the insert of this invention is useful. As indicated in the above mentioned patents, the coupling segments, which are made out of metal, may be bolted together to form the single, circular coupling or may be attached together by suitable hinge configurations and locked together with bolts, etc.
When conventional casings are utilized to connect water pipes and similar fluid carrying pipes, it is sometimes necessary to seal the adjacent pipe ends more firmly than is possible using conventional gaskets. In addition, it may be desirable to seal the pipe ends together with a seal which is of a different resiliency than the gaskets typically used. This may be particularly useful in installations where the pipe ends tend to move or flex relative to each other.
Thus, attempts have been made in the past to provide C-cross-section shaped resilient gaskets that are utilized within conventional pipe coupling housings, with a central tongue portion, which can extend within or bridge over the slight gap that normally occurs between two aligned pipes that are to be coupled together. An example of this is a coupling gasket formed in a C-shaped cross-section with a central tongue extending inwardly between the spaced apart legs of the gasket. This forms a unitary or integral molded gasket with a central tongue for engaging the adjacent pipe ends. With such construction, rigidifying the tongue sufficiently so that it maintains its position and pressure against the pipes has been accomplished by molding a flat ring within the tongue. The flat ring extends in the axial direction from one side or face of the tongue to the other face.
The formation of an integral gasket and tongue, particularly with a flat ring molded within the tongue for rigidity or stability purposes, is relatively expensive. In addition, that construction requires maintaining a relatively large inventory so that gaskets with and without tongues are available in a number of sizes to fit different couplings. That is, the warehouse or manufacturer or the contractor, utilizing such gaskets, must stock double the number of ordinary gaskets that might be kept, because the tongue is needed in some coupling installations, but not in others. That substantially increases inventory expense and, also, the expense of manufacturing because of the need for additional molds for molding the rubber-like gaskets and the need for different size metal reinforcing rings for the tongues.
Thus, this invention is concerned with providing a tongue-like insert which may be optionally used. This insert may be manually inserted or removed from a conventional coupling gasket when desired.